Hach-Lange SI792 C, SI792x C, SI792x C-FF, SI792x C-PA User Manual - Manual (Page 30)

Installation
28
3.6 HART communication connection
DANGER
Explosion hazard. Never connect items to the transmitter that are
not specified on the control drawing. Do not connect or
disconnect any equipment unless power has been switched off or
the area is known to be non-hazardous.
DANGER
The si792x transmitter must be used with an explosion-proof
HART communication device. Refer to the appropriate control
drawing for the location of the HART (Rosemount) device.
The handheld HART communication device can only be connected to
the transmitter in US Class I, Division 1 classified locations (permitted
only by FM). Do not connect the handheld Hart communication device
to the transmitter in any Zone or Canadian Class I, Division 1 classified
location. Refer to
Figure 4 on page 24 for the connector location.